• Journal of Korean Society on Water Environment
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• v.34 no.1
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• pp.57-66
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• 2018

Water disasters such as flash floods and inundation caused by localized heavy rainfall in urban areas have a large impact on climate change but are also closely related to the increase in impervious areas as pointed out in domestic and international studies. It is difficult to secure natural green areas in urban areas that have already been developed. So, urban regeneration can be expected using water management optimized with technologies to secure infiltration and storage capacity such as Low-Impact Development technology. In this study, the water cycle improvement ability was confirmed by applying the LID technology within the district unit plan of the environmentally friendly village, and the economic feasibility of LID application was analyzed by estimating the costs and benefits of installing the facilities. The site was planned to conserve sufficient green and plans for securing the watershed infiltration and storage capacity were formulated with the application of additional LID technology, such as infiltration trenches, rain barrels and permeable pavements. The LID design method applicable to the site was established, and the water balance of the watershed was analyzed through simulations of the SWMM model. The water circulation improvement effect was confirmed through the water balance analysis, and the cost-benefits were determined according to the estimation method, and the economic analysis was conducted. This study confirms that the investment of LID technology is economically feasible for the hydrological improvement effect of the housing complex.

• Journal of the Korean Home Economics Association
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• v.29 no.2
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• pp.155-167
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• 1991

There have been many cooperative meetings from the past in our country. "Kye" is the most popular and current exisiting meeting of them in our society. Therefore, study of "Kye" at this point will be useful for life, attitude, value in urban area. The concret purposes of this study are to investigate: (1) Participationg rate of the city housewives' "Key" meeting. (2) Purpose of the city housewives' "Kye" meeting. (3) The order of the most influential variable among the socio-economic variables, the family life cycle variables, and the residence variables on the city housewives' "Kye" meeting. For the purpose of this main study, 600 questionnaires were distributed to housewives living in Seoul and collected during the six months, from November, 1989 to April, 1990. And method of data analysis for this survey was Multiple Regression. The major results are as follows: (1) Participating rate of city housewives' "Kye" meeting is 52.2%. (2) Purpose of city housewives' "Kye" meeting is in the order of "for saving", "for friendly gatherings", "for commodity purchase". The order of the most influential factor (3) among the socio-economic variables is the age of respondents (β:.187), the average income of all house members(β:.177), and the schooling years (β:-.147), (4) among the family life cycle variables is the family life cycle(β:.261), number of children(β:-.212), (5) among the residence variables is the duration of current residence(β:.221), kind of house(β:.118). Comparing the past studies, the purpose of "Key" meetings has changed from the family centered events method such as worship or marriage of family members to out of the family and friends centered events such as social gatherings among the people in urban community.

• Journal of the Korean housing association
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• v.10 no.4
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• pp.1-10
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• 1999

The purpose of this study was to investigate the environmental factors having a influence on the preference of residential district and to furnish basic information for the successful settlement. For the purpose, residential preference and values on the residential district were estimated according to the housing life cycle. Data were collected through questionnaires designed for this study, and the objects of this research were university students. To analyze the data were used spsswin program. The major results were as follows. 1. According to the housing life cycle, there were significant differences in the preference of the residential district, living area and housing type in the future. Metropolitan and seoul, residential area and commercial area, apartment, office-hotel and row house were preferred in the housing formative. In the stable period, seoul and metropolitan, tower apartment, residential area were preferred. But in the housing reductive period, they preferred a green zone in the rural, the detached house. 2. The degree of consideration of living convenience facilities was high in the housing formative period. Both education-leisure, business facilities and marketing facilities were highly valuated in the housing stable period. But the value of welfare facilities was high in the housing reductive period. 3. The 4 dimensions of values in environmental conditions were extracted through factor analysis. They were natural, human, social, and economic factors. According to the housing life cycle, there were significant differences in factors being considered as the environmental conditions. The values of human and economic factors were high in the housing formative and stable period. Natural factor were highly considered in the housing reductive period.

• Journal of the Korean Solar Energy Society
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• v.36 no.5
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• pp.73-89
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• 2016

To assure maximum economic benefits and the energy performance of solar water heating systems, the proper sizing of components and operating conditions need to be optimized. In recent years, a number of studies to design optimally solar water heating systems have been tried. This paper presents a design method for optimizing the various capacity-related and installation-related design variables based on life cycle cost using a genetic algorithm. The design variables considered in this study included the types and numbers of solar collector and auxiliary heaters; the types of storage tanks and heat exchangers; the solar collector slope; mass flow rates of the fluid on the hot and cold sides. The suggested method was applied for optimizing a solar water heating system for an elementary school in Seoul, South Korea. In addition, the effectiveness of the proposed optimization method was assessed by analyzing the obtained optimal solutions of six case studies, each of which was simulated with different solar fractions. It is observed that a trade-off between the equipment cost and the energy cost results in an optimal design that yields the lowest life cycle cost. Therefore, it could be helpful to apply the optimal solar water heating system by comparing the various design solutions obtained by using the optimization method instead of the engineer's experience and intuition.

• Journal of Technology Innovation
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• v.20 no.2
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• pp.135-159
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• 2012

To the analysis and discussion whether to conceptualization between the basis and LCM(Life cycle management) of patentability decisions and evergreening through research on patent application strategies and litigation cases. The Stakeholders have said that the LCM and evergreening strategies are an innovative effort to develop new pharmaceuticals, while others say that it is an effort to block generic pharmaceuticals from entering the market and permanently dominate the market by generic pharmaceuticals manufacturers or health economic perspectives. To achieve the goal of research, to discuss for conceptualization LCM and Evergreening strategies through patent application strategies for 14 pharmaceuticals for APIs and case studies for litigations. As a results, the LCM is getting patent rights for the results of research at the initial R&D stage and as such this shall be regarded as part of an effort for technology innovation. However, Evergreening is granting patent rights for the results by making high permission barrier to prevent the market entry of generic pharmaceuticals in the late development period during the pharmaceuticals development process or after their launch. This may lead to the problem of getting weak in health economic aspects and consumer welfare aspects by lowering the market accessibility of cheap generic pharmaceuticals.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.6
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• pp.334-342
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• 2016

Conventional eco-design has been implemented based only on the environmental aspects of a product. Key components of a product identified from the analysis of the environmental aspects have been the target for improvement in the conventional eco-design. The use of eco-design index (EDI) considering both the environmental and economic aspects, and utility value (UV) of a product can be envisaged as an alternative way of implementing and assessing the eco-design. The objective of this study was to propose the logic of the EDI and apply it to the components for performing printing function of the multi-function printer. The EDI was formulated by quantifying the UV, life cycle environmental impact (LCE) and life cycle cost (LCC) of the components of a product, here components of the printer. Of the eight components investigated, roller was identified as the best performing consumable in both the environmental and economic aspects. However, its UV was the lowest among the eight. The EDI of the roller was mere $4^{th}$ in ranking out of the eight. Transfer belt ranked $8^{th}$ and $5^{th}$ in the environmental and economic aspects, respectively, while $2^{nd}$ in the utility value with its EDI ranked $3^{rd}$. This indicates that not only the environmental aspects but also economic and utility value aspects should be considered when identifying the key components for improvement in the eco-design.

• Journal of IKEEE
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• v.23 no.4
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• pp.1208-1217
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• 2019

The life-cycle prediction of the sub-module which is the unit system of MMC is very important from the viewpoint of maintenance and economic feasibility of HVDC system. However, the life-cycle prediction that considers only the type, number and combination of parts is a generalized result that does not take into account the operating condition of the sub-module, and may significantly differ from the life-cycle of the actual one. Therefore, we design a fault tree for the purpose of reflecting the operation characteristics of the full-bridge sub-module and apply the MIL-HDBK-217F to the failure rate of the basic event to predict the life-cycle of the full-bridge sub-module. It compares the life-cycle expectancy of the conventional failure rate analysis with the proposed fault-tree analysis and compares the lifetime according to whether the redundancy of the full-bridge sub-module is considered.

• The KSFM Journal of Fluid Machinery
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• v.20 no.1
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• pp.41-47
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• 2017

This study aimed to analyze organic Rankine cycle(ORC) which recovers discarded heat from a gas turbine based combined cycle cogeneration(CC-cogen) plant in terms of both performance and economics. The nominal electric power of the CC-cogen plant is around $120MW_e$, and heat for district heating is $153MW_{th}$. The major purpose of this study is to compare various options in selecting heat source of the ORC. Three heat sources were compared. Case 1 uses the exhaust gas from the HRSG, which is purely wasted to environment in normal plant operation without ORC. Case 2 also uses the exhaust gas from the HRSG. On the other hand, in this case, the DH economizer, which is located at the end of the HRSG, does not operate. Case 3 generates power using some of the district heating water which is supplied to consumers. The estimated ORC power generation ranges between 0.3 to 2.3% of the power generation capacity of the CC-cogen plant. Overall, Case 3 is evaluated to be better than other two options in terms of system design flexibility and power generation capacity.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.117-126
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• 2015

This paper is to analyze an integrated production and inventory model in a single-vendor multi-buyer supply chain. The vendor is defined as the manufacturer and the buyers as the retailers. The product that the manufacturer produces is supplied to the retailers with constant periodic time interval. The production rate of the manufacturer is constant for the time. The demand of the retailers is constant for the time. The cycle time of the vendor is defined as the elapsed time from the start of the production to the start of the next production, while the cycle times of the buyer as the elapsed time between the adjacent supply times from the vendor to the buyer. The cycle times of the vendor and the buyers that minimizes the total cost in a supply chain are analyzed. The cost factors are the production setup cost and the inventory holding cost of the manufacturer, the ordering cost and the inventory holding cost of the retailers. The cycle time of the vendor is investigated through the cycle time that satisfies economic production quantity with the production setup cost and the inventory holding cost of the manufacturer. An integrated production and inventory model is formulated, and an algorithm is developed. An numerical example is presented to explain the algorithm. The solution of the algorithm for the numerical examples is compared with that of genetic algorithm. Numerical example shows that the vendor and the buyers can save cost by integrated decision making.

• Journal of The Korean Association For Science Education
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• v.21 no.5
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• pp.893-905
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• 2001

Korean students ranked the 3rd out of 32 participating countries in the first cycle of PISA(Programme for International Student Assessment) science field, which assessed 15-years-old students' scientific literacy. PISA developed several variables such as parents' socio-economic status, parents' educational attainment, family wealth, and cultural possession, to investigate the effects of background variables on scientific literacy. On the other hand, motivation and engagement in science study were not given much attention, partly because science was the minor area in the first cycle of PISA. Therefore, PISA Korea developed a series of variables to collect data on students' learning motives and out-of-school activities in science as a national option. The results are as followings. First, Korea was found to be one of the PISA participating countries with the scientific literacy achievement least influenced by parents' socio-economic status, family wealth, and parents' cultural possession. Second, the degree of achievement in scientific literacy according to parents' educational attainment was in a positive correlation, similar to the overall tendency of PISA. Third, the most crucial learning motive for Korean students was their desire to develop scientific thinking abilities or obtain science knowledge. On the other hand, choosing jobs in the field of science or parental expectation was the least important learning motive. In particular, the motive for scientific learning was found to have a positive relationship with the degree of scientific literacy achievement. Therefore, the higher the students achievement, the stronger the motive for scientific learning in order to develop their ability to think scientifically or acquire science knowledge. Fourth, Korean students were shown to participate very little in out-of-school scientific activities other than watching TV programs related to science. Whatever the activities may be, the more actively involved students are in out-of-school scientific activities, the higher their scientific literacy achievement. Fifth, Korean girls were rather passive compared to boys in all areas, including science learning motive and out-of-school scientific activities. The gender difference was especially more pronounced in out-of-school scientific activities with wider gaps in such activities as reading scientific books or articles and visiting science-related web sites.